Kungsträdgården Park in Stockholm, where the We Are Sthlm festival is held.
Photograph: Aivar Pertel/Alamy Stock Photo/Alamy Stock Photo

Sweden is proud of its reputation for being one of the world’s most progressive and egalitarian nations, and for a long time Kajsa Norman thought that its main defect was being rather “boring”. As an investigative journalist, she preferred more challenging environments, such as Zimbabwe. But while abroad she heard of an incident in Sweden “so disturbing and strange” that she felt compelled to investigate. What she found shook her faith in her country.

The annual We Are Sthlm music festival attracts some 200,000 people, mostly aged between 13 and 19, to Kungsträdgården Park in central Stockholm. On a balmy evening in August 2015, a middle-aged psychologist, whom the author calls Hans, as he wishes to remain anonymous, took his teenage relatives to the festival. As twilight fell, he noticed how groups of men and boys appeared and began “eyeing the young girls in hot pants”. During the evening he saw girl after girl stagger out from the crowd to ask for help from the security guards after being sexually assaulted.

Afterwards Hans was haunted by the memory of “watching packs of predators hunt helpless prey”, and was shocked that nothing appeared in the press the next day. When he emailed the Dagens Nyheter newspaper, a journalist called him. Although she sounded interested, when he mentioned that “the vast majority” of the perpetrators “appeared to be Afghans”, her tone became “noticeably colder”. No article appeared, leaving Hans angry that “in a country that claims to be one of the most feminist places on earth”, no one cared.

Eventually he contacted an alternative news website run by a former counsellor for the nationalist Sweden Democrats, whom Norman describes as a “dissident”. The resulting story caused a storm of controversy, with accusations of both a media and a police cover-up.

This hard-hitting book is permeated by a deep sense of disillusionment. Norman argues that in its quest to achieve an ideal society, Sweden has created a culture of conformism that suppresses inconvenient truths and breeds moral cowardice. Her book is a plea for more honesty and openness: “Swedish society is far from a pluralistic utopia.” She is undoubtedly a powerful writer, but at times the complexity of the issues she raises cries out for a more nuanced discussion.